http://www.openswan.org/

# yum install openswan
	

vi /etc/sysctl.conf
net.ipv4.ip_forward = 1
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.send_redirects = 0
	

ipsec newhostkey --output /etc/ipsec.secert